There are many difficulties encountered by physicians and nurses in the process of cutting an umbilical cord shortly after the moment of birth. These difficulties cannot be overcome easily by current technology.
Difficulties arise due to the fact that at the moment of birth there is a great deal of fluid present, including blood and amniotic fluid from the mother, making the physician's gloved hands slippery. The procedure of clamping and cutting an umbilical cord first calls for the placement of a small first clamp close to the newborn to stop the flow of blood in the cord and to clamp off what will become a first severed end of the cord (the end of the cord connected to the infant). The combination of the small clamp size and the fluid on the physician's gloved hands creates difficulty in applying the first clamp. In some cases the physician cannot adequately close the clamp around the cord forcing the temporary use of a metal hemostat in its place. Replacing the hemostat with a clamp requires placing the clamp on the cord and re-cutting the cord stump. This procedure is often done as late as the infant's arrival in the nursery.
Next, a second clamp must be placed by the physician sufficiently distal to the first to allow a cut to be made between the first and second clamps and to clamp off what will become a second severed end of the cord (the end of the cord connected to the placenta). Generally, this procedure is also made by the deliverer while balancing the neonate in one arm. This procedure often presents the same difficulties as described above.
Additional difficulties are presented because the cord is engorged with blood at birth and when the cord is severed blood commonly spurts from the incision spattering the medical team with droplets. As a consequence, it is routine practice for the medical staff to wear protective eye wear during the process for the purpose of protecting them from exposure to blood. However, sometimes these protective elements dangerously block the view of the wearer (who may be a physician).
Routinely samples of blood from the cord are collected for chemical and biological assay. Such assays may include testing to determine whether the newborn is subject to possible genetically transmitted diseases. Currently two alternative methods are used to collect cord blood samples. These methods include draining the blood from the cord segment directly into an open vial or extracting the blood directly from the cord by using a syringe and needle.
The draining method requires holding an open ended sample vial below the second severed end of the cord (the end connected to the placenta) while releasing the clamp from that severed end and directing the blood flow from that severed end into the sample vial. In most cases the cord segment must be hand "milked" by squeezing the cord such that the blood in the segment flows toward the vial. This "milking" action causes the flow of many contaminants in addition to the desired blood into the vial. Such contaminants include the mother's vaginal blood, amniotic fluids and Wharton's gel, all of which may affect the testing of the cord blood sample. As the complexity and sensitivity of the genetic tests increase, the absence of contamination in the sample becomes more important.
The extracting method requires using a syringe and needle to remove the blood directly from the cord. The needle is used to puncture the cord and the syringe is used to collect a blood sample. Care must be taken to prevent inadvertent needle sticks (which can lead to blood exposure). The contents of the syringe must then be transferred into appropriate vials. This transfer requires further steps of manipulating needles and syringes which create additional risks of blood exposure.
In addition, both of these blood collection methods leave contamination from blood on the external portions of the vials making it difficult to apply or retrieve patient labels and increasing exposure to blood. Thus, there are many problems associated with the current methods of collecting blood samples from umbilical cords.
A device has been designed, fabricated and tested which provides a much improved method of collecting samples of blood from an umbilical cord. The purpose of this device is to provide: (1) simple one handed clamping of umbilical cords at birth, regardless of size; (2) cutting umbilical cords; and (3) automatically delivering adequate samples of uncontaminated cord blood suitable for current laboratory analysis to protected containers with little or no exposure to inadvertent blood splash or to sharp objects.
Embodiments of the device have been assembled, sterilized, and tested by physicians in cases of both vaginal and caesarian births. The devices have effectively collected samples of cord blood. Duplicate samples of blood taken by conventional methods were tested as a control to assure the integrity of the device. The clinical testing was performed under controlled conditions during the last quarter of 1991.